Fig. 5

Carrier density and ratio of surface carrier population to the total one. a The line density of hole carriers that is plotted as a function of gate biases for a 3 nm × 3 nm and a 8 nm × 8 nm cross-section. A negatively increasing gate voltage not only fills more carriers but generally creates stronger band bending in channels, increasing the chance for carriers to experience the corner effect. b The ratio of surface carrier (staying within 1.0 nm from channel surfaces) population to the total one that is plotted as a function of line densities of carriers for a 3 nm × 3 nm and a 8 nm × 8 nm cross-section. Although the corner effect may not be remarkable in narrower channels where cross-sections are not large enough to have clear band bending, the chance for the surface roughness scattering would be still high since more carriers are then placed near channel surfaces